lib/libminlib/fslib.c

   1 /* fslib.c - routines needed by fs and fs utilities */
   2
   3 #include <minix/config.h>       /* for unused stuff in <minix/type.h> :-( */
   4 #include <limits.h>
   5 #include <dirent.h>
   6 #include <sys/types.h>
   7 #include <minix/const.h>
   8 #include <minix/type.h>         /* for unshort :-( */
   9 #include <minix/sysutil.h>
  10 #include <minix/minlib.h>
  11 #include "mfs/const.h"          /* depends of -I flag in Makefile */
  12 #include "mfs/type.h"           /* ditto */
  13 #include "mfs/inode.h"          /* ditto */
  14 #include "mfs/super.h"
  15 #include <minix/fslib.h>
  16 #include <sys/stat.h>
  17
  18 /* The next routine is copied from fsck.c and mkfs.c...  (Re)define some
  19  * things for consistency.  Some things should be done better.
  20  */
  21
  22 /* Convert from bit count to a block count. The usual expression
  23  *
  24  *      (nr_bits + (1 << BITMAPSHIFT) - 1) >> BITMAPSHIFT
  25  *
  26  * doesn't work because of overflow.
  27  *
  28  * Other overflow bugs, such as the expression for N_ILIST overflowing when
  29  * s_inodes is just over V*_INODES_PER_BLOCK less than the maximum+1, are not
  30  * fixed yet, because that number of inodes is silly.
  31  */
  32 /* The above comment doesn't all apply now bit_t is long.  Overflow is now
  33  * unlikely, but negative bit counts are now possible (though unlikely)
  34  * and give silly results.
  35  */
  36 int bitmapsize(nr_bits, block_size)
  37 bit_t nr_bits;
  38 int block_size;
  39 {
  40   int nr_blocks;
  41
  42   nr_blocks = (int) (nr_bits / FS_BITS_PER_BLOCK(block_size));
  43   if (((bit_t) nr_blocks * FS_BITS_PER_BLOCK(block_size)) < nr_bits) ++nr_blocks;
  44   return(nr_blocks);
  45 }
  46
  47 uint8_t fs_mode_to_type(mode_t mode)
  48 {
  49         if(S_ISREG(mode)) return DT_REG;
  50         else if(S_ISDIR(mode)) return DT_DIR;
  51         else if(S_ISLNK(mode)) return DT_LNK;
  52         else if(S_ISCHR(mode)) return DT_CHR;
  53         else if(S_ISBLK(mode)) return DT_BLK;
  54         else if(S_ISFIFO(mode)) return DT_FIFO;
  55         else if(S_ISSOCK(mode)) return DT_SOCK;
  56
  57         panic("unknown type, mode 0x%x", mode);
  58 }
  59